Rock-drill.



PATENTED MAY 15,1906. W. STURM. lROCK DRILL.

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WILLIAM STURM, 0E CHICAGO, ILLINOIS.

Rocmb||i |p Specication of Letters# Patent. Application filed March11,1905'. Serial Np. 249602.

Patented May 15,` 1906.

To all whom it may concern:

Be it knownthat I, WILLIAM STURM, a citizen of the UnitedStates,residing at Chicago,` in the county of Cook and State of Illinois, haveinvented a certain new and useful Imrovement in Rock-Drills, of whichthe fol-I owing is a full, clear, concise, and exact de-I scription,reference being had to the accompanying drawings, forming a part of thisspecification.

My invention relates to rock-drills adapted for attachment to the end ofa drill-rod.

Prominent objects of the invention are to provide a' simple, practical,and inexpensive form of rock-drills to arrange for the easy and readyrenewing or repairing of the cutting member of the drill, -to secure ahighly efficient and effective cutting action, and to accomplish theforegoing and'other desirable ends'in a simple and expeditious manner.

In the accompanying drawings, Figure 1 1s a view, partly in elevationand artly in longitudinal section, of a drill-roti) and drill embodyingmy invention. Fig. 2 is a top view of the same. Fig, 3 is a perspectiveview of one of the cutters. Fig. 4 is a top view of the same. Y

The drill shown comprises a drill-rod 1, provided with the drillcomprising a shank 2, desirably of rectangular cross-section, as' shownin Fig. 2. The end of the shank 2 is provided with a plurality ofcutters 3 3, desirabl four in number, and these are fitted into s ots orrecesses formed at the end of the shank 2. The four cutters fareconveniently arranged on the diagonale .of the rectangle formed by thecross-section of the shank, as shown in Fig. 2. Each cutter vis providedwith a horizontal cutting edge 3 and also with a peripheral cutting edge4 at the outer or peripheral end of the cutting edge 3a. The inner ends5 5 of the cutters 3 3 are flared outwardly, as shown in Figs. land 3,and the sockets in the shank 2 are correspondingly flared to receivethem. These cutters are also tapered sli htly so as to accommodate alookin screw-p ug 6, which fits centrally in the dri l between thevarious cutters and has its inner end threaded and screwed into athreaded socket in lthe shank 2.44 Thus-'the cutters 5 5 are locked inposition by the threaded locking screw-plug 6, holding them. firmly intheir sockets. The ping 6 is desirably provided with a cutting edge 7.The plug 6 is held firmly inposition by a setscrew 8. Thus the cuttersare bodily removable from the shank to permit them to be withdrawn andrepaired or replaced. When in position in the shank, ltheyare firmlyheld and practically wedged in their sockets. The periplheral cuttingedges 4 4, together with the orizontal cutting edges 3 3 and 7, form aneffective and efficient cutting arrangement. v

Thus it will be seen that the drill embodying my invention has theadvantage of permitting the cutters to be made of any desiredmaterial-as, for example, Isteelwhich can be tempered. as desired, andthat these cutters can be inserted in the drill for use and removed andrepaired or replaced as desired.

Changes and modifications can be'made in the device herein describedwithout departin from the spirit of my invention.

hat I claim isv 1. A rock-drill comprising a shank, a plurality ofremovable cutters arran ed on opposite sides of the center of the dri,

edges, and a central lockin device for locking said cutters in their socets, said locking device being also provided with a cuttin edge locatedbetween oppositely-dispose cutters.

2. A rock-drill comprising a shank, a plurality of removable cuttersarranged radially on opposite sides of the center, of rotation of' thedrill, and a central locking device for locking said cutters in theirsockets, said lockin device having a cutting edge which exten s betweenoppositely-disposed radial cutters, and thereby forms a continuous orsubstantially continuous strai ht cuttin -surface from one ed e ofthedrilI tov the ot er.

3. A rock-dril comprising a shank rovided. with a plurality of socketsor' s ots flared outwardly in a radial direction at their inner ends, incombination with a corresponding number of cutters adapted to fit insaid slots, and similarly flared, and a centrallydisposed locking devicefor forcing said cutters outwardly and thereby locking them in theirsockets. l In witness whereofI I hereunto subscribe my name this 4th dayof March, A. D. 1905.

vWILLIAM STURM.

Witnesses:

A. M. BELFIELD, I. C. LEE.

said cut- -y ters being provided with peripheral cutting IOO

